The present application is based on French patent application no. 01/02991, filed on Mar. 2, 2001, which is hereby incorporated by reference herein, int its entirety.
1. Field of the Invention
The invention relates to a method and device for inserting, into a receiving housing such as a cavity, or for depositing on a surface, continuous fibers, for example glass fibers, in expanded form, with a view to acoustically and/or thermally insulating the deposition housing or environment.
2. Description of the Background
It is known from U.S. Pat. No. 4,569,471, for deadening the noise of an acoustic exhaust muffler for an engine, to fill the space surrounding the exhaust gas discharge cylinder with glass fibers, which fibers consist of continuous glass filaments supplied from a yarn roving and are in the form of a bulked product. There, a glass yarn roving is treated by wheels for stretching out/paying out the yarn, and for guiding the yarn, a braking wheel for controlling the tension in the yarn, and a compressed air apparatus for spraying the yarn into the space that is to be filled, the air injected into the apparatus allowing the filaments to be separated, entangled and sprayed.
However, this device, installed at a factory for the mass-production of exhaust mufflers requires numerous take-up elements for stretching out, guiding and controlling the tension in the yarn as far as the spraying apparatus. Moreover, it is not possible for this device to be used in other applications of filling or depositing, the receiving elements (cavity or surface) of which are too bulky to be filled in factory, or which are fixed.
It is therefore an object of the invention to provide a device for filling or depositing expanded fibers, which is simpler to use and more compact than known devices, thus making it lighter in weight and portable.
It is another object of the invention to provide a method and device for filling or depositing expanded fibers, which is easy to handle and to direct, therefore allowing the fibers to be sprayed in any direction.
According to a feature of the invention, a device comprises a spraying apparatus for charging, in expanded form, fibers from at least one bundle of fibers taken from at least one roving, the apparatus comprising a portable tool having a manual gripping element, the portable tool comprising a nozzle for spraying the fibers of the at least one bundle; an air supply device connected for supplying air to the nozzle so as to expand fibers of a bundle therein; an extraction system configured to hold the at least one bundle and feed the at least one bundle to the nozzle; and an inlet guide positioned to guide the at least one bundle to the extraction system.
This device is therefore portable, which has the advantage of enabling it to be used on receiving elements which cannot be transported or which are difficult to access.
The bundle of the roving may be formed of a number of continuous or discontinuous filaments made of glass or thermoplastic. Depending on the application, it may be envisaged that the device will comprise several rovings, the bundles of which are paid out and bulked by the spraying apparatus together and simultaneously.
In the case of the use of a single roving, the latter may be portable, being placed in a basket.
According to one feature, the bundle extraction system has two cylindrical rollers rotating in opposite directions and between which the bundle passes, and an outlet guide arranged at the outlet of the rollers and which takes up the bundle. The rotational speed of the rollers gives the bundle its linear speed of travel.
According to another feature, a device for guiding the bundle towards the inlet of the apparatus is provided an the outside of the body of the apparatus and consists, for example, of an eyelet or a flexible tube. In the case of several bundles, a device for guiding the bundles is provided on the outside of the body of the apparatus and consists of a row of eyelets arranged along an axis parallel to the axes of rotation of the rollers.
Preferrably, there is provided a debundling system which consists of an associated spreader bar system at the roving outlet or at the inlet to the spraying apparatus.
The extraction system advantageously operates using a pneumatic motor.
According to another feature, the spraying apparatus has the form of a gun, the handle of which constitutes the holding element and houses the pneumatic motor.
Preferably the air supply to the nozzle and the air supply to the motor came from the same source, such as a pneumatic compressor, so as to simplify the device as far as possible.
Advantageously, means of recovering air which has been exhausted from the pneumatic motor, consist of a pipe which is connected to the exhaust region of the pneumatic motor and is arranged to open, laterally to the outlet guide.